The present invention relates to a coaxial cable output terminal safety plug device for use in cable television systems (CATV), subscription television systems (STV) and master antenna TV systems (MATV) to releasably block up any signal output terminal which is not in use.
Regular cable television systems generally utilize coaxial cables to transmit audio signal to subscribers. Therefore, transformer of multiple output terminals and impedance matching and amplifying device must be used so that audio signal can be transmitted to each subscriber through coaxial cable. Because the number of subscribers is generally not equal to the number of output terminals, a plug which has an impedance matching device must be used to block up each output terminal which is not in use, so as to eliminate impedance matching problems between signal output coaxial cable and subscriber's coaxial cable.
The conventional plug which is used to block up a coaxial cable output terminal may be easily removed from an output terminal and a non-subscriber can easily connect an output terminal to a TV without paying any fee. Therefore, there is developed a kind of safety plug which requires a special tool to fastened in or remove from a coaxial cable signal output terminal and can effectively protect from piracy. However, this type of safety plug is expensive and easy to damage.